Spring for sprinkler head



FIG. 1 is a front elevational view of a spring for a sprinkler head showing my new design, a rear elevational view thereof being a same image;

FIG. 2 is a right side elevational view thereof; a left side elevational view thereof being a same image;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof. 

CLAIM The ornamental design for a spring for a sprinkler head, as shown and described. 